The present invention relates to a device for scraping the surface of belt conveyors.
It is known that more or less thick deposits accumulate over the surfaces of belt conveyors, depending on the stickiness of the conveyed materials.
Presently the most common devices used for cleaning the belt surface include scrapers substantially formed by a plurality of plates carrying blade-shaped scrapers--usually of steel--at the ends contacting the belt, to remove the material accumulated over the belt by means of a scraping action.
The scrapers or cleaning devices actually on the market are generally provided with plates each pivotally mounted on rubber springs, and this arrangement results in a quick deterioration of their elastic properties because of the hysteresis of the elastomeric material they are made of, when the belt operating speed is faster than 3 m/s.
Moreover in all cases the blades and the associated elastic members are carried by a pipe rigidly connected to the conveyor frame, thus requiring interventions for adjusting the whole system as the scrapers wear out.
The object of the present invention is that to overcome said shortcomings by providing a decidly more convenient and rational scraping device, that does not require particular and frequent adjustments, said device being further provided with scraping members capable of automatically self-adjusting and continuously adapting themselves to the belt conveyor moving surface.
In case of reversible belts, it is known that the existing scrapers for such belts do not allow for an automatic disengagement of the scraping devices which continue to operate and therefore wear out the scraper members when the running direction of the belt is reversed.
It is quite common the case in which a cleaning action is required on the upper surface of the belt lower (or return) section in order to intercept also the material that has fallen down from the transporting section.
In some cases, it may be desirable that two scraping devices are located in series on the same scraper for an increased cleaning action.